Liquid crystal screens use liquid crystal materials as basic components. The liquid crystal materials are filled between two parallel plates. The arrangement conditions of molecules inside the liquid crystal material are changed by using voltage to achieve the purpose of shading and transmitting light, so as to display well-proportioned images with different shades. The liquid crystal screens are widely applied to TVs, mobile phones, computers, outdoor advertisement screens and other products due to their advantages of low power consumption, good picture display effect and the like. Liquid crystal molecules of the liquid crystal screens are non-luminous, so the liquid crystal screens need special backlight sources for providing light to display pictures.
In order to improve the display quality, sense of display layering and contrast ratio of pictures, a backlight source usually employs a dynamic backlight control method. The specific implementation process is as follows: a backlight module of the backlight source is divided into n subregions, a backlight value of each subregion is calculated according to image information of the subregion, and an average value of the backlight values of the n subregions is calculated, so that a gain value is determined according to the average value, and the backlight values are adjusted according to the gain value, so as to allow the backlight of the n subregions to generate corresponding brightness.
During the implementation of the above backlight control process, at least the following problems have been found: in the above method, the n subregions all correspond to one gain value, and the corresponding backlight values are adjusted according to the gain value, which will increase the brightness of a low-brightness picture portion while meeting the brightness of a high-brightness picture portion, so that the brightness of the low-brightness picture portion is too high, the requirements on different image quality enhancements in different display regions of the liquid crystal screen cannot be met, and the display quality and the sense of display layering of pictures are reduced.